Exploring the Risks of the Large Hadron Collider

[chippy!]

You need to keep in mind that creating black holes is something they WANT. This isn't the issue. If GR is correct in this energy scale, then creating these micro black holes would not be surprising. I know of many people who would LOVE to be able to create AND detect them.

The issue is (i) the nature of such black holes and (ii) that they become stable and can create a catastrophe. This is the scenario that is creating such a brouhaha in the media. This is what has been argued to be extremely unlikely. It is as likely as you spontaneously vanishing.

Zz.

ok thanks for your response. i take it that the odds are way against these stable BH's then?
well it still makes me feel a bit uneasy that we might be creating these black holes whatever the size to be honest.
are the scientists at all aprehensive? becasue didnt one of them say they don't actually know what will happen in this experiment?

 

[vanesch]

You need to keep in mind that creating black holes is something they WANT. This isn't the issue. If GR is correct in this energy scale, then creating these micro black holes would not be surprising.

Uh, it would be a very peculiar kind of GR, in many dimensions, which are curled up on larger scales than we would think, which would allow black holes to be created in the first place. Most "standard" physics wouldn't even come close in creating a black hole in the LHC, or even in the VLHC (Very Large Hadron Collider) or the ILHC (Insanely Large Hadron Collider). Creating black holes at "puny" energies of 14 TeV as compared to the Planck scale is by all "normal" means entirely impossible, and you have to twist and turn spacetime in funny shapes for it to become even conceivable (which is what theorists have done). Of course, this means that it is not *inconceivable*, as it has been conceived theoretically. If ever there is a signature of black hole creation in the LHC, then the theorists that wrote this down won the biggest bet they ever took.

But, based upon the same kind of theoretical reasoning, and on much firmer grounds, we know that IF micro black holes exist, they should evaporate almost instantaneously. So for micro black holes to form, and for them not to evaporate, would need two giant leaps out of established theory.

Finally, EVEN if this were conceivable, it cannot happen very often, as Zz pointed out, because "the moon is still there".

 

[ZapperZ]

ok thanks for your response. i take it that the odds are way against these stable BH's then?
well it still makes me feel a bit uneasy that we might be creating these black holes whatever the size to be honest.
are the scientists at all aprehensive? becasue didnt one of them say they don't actually know what will happen in this experiment?

Look, one of my friends here at work will be going there to become an assistant physics coordinator for ATLAS. Do you think he'll be there if he is even a little bit apprehensive? There will be hundreds of people working there during first collision. Do you think they are at all apprehensive? I would be there too if I can find a rational and valid reason for being there (I have none). I have absolutely zero apprehension. And as I've said earlier, the person most concerned about my safety and well-being is ... ME!

So you can draw up your own conclusion from this.

Zz.

 

[ZapperZ]

Uh, it would be a very peculiar kind of GR, in many dimensions, which are curled up on larger scales than we would think, which would allow black holes to be created in the first place. Most "standard" physics wouldn't even come close in creating a black hole in the LHC, or even in the VLHC (Very Large Hadron Collider) or the ILHC (Insanely Large Hadron Collider). Creating black holes at "puny" energies of 14 TeV as compared to the Planck scale is by all "normal" means entirely impossible, and you have to twist and turn spacetime in funny shapes for it to become even conceivable (which is what theorists have done). Of course, this means that it is not *inconceivable*, as it has been conceived theoretically. If ever there is a signature of black hole creation in the LHC, then the theorists that wrote this down won the biggest bet they ever took.

I don't think it is based on any "standard" physics, If you read the Peskin link, he describe one scenario for such formation, which is what you have in mind, I think:

Particle collisions at energies above the Planck scale must create black holes, because they put large amounts of energy within a small enough region (the so-called Schwarzschild radius). Giddings and Thomas [6] and Dimopoulos and Landsberg [7] realized that this logic, applied to the ADD model, implies that high-energy collisions at TeV energies should produce black holes. They did not consider this a danger but rather an exciting possibility. They imagined that the black holes would glow with a temperature of about 1 TeV/kB, emit large numbers of quarks, leptons, and bosons through Hawking radiation [8], and evaporate in 10-26 s. This process would produce unique and unmistakable events detectable by the LHC experiments.

Zz.

 

[mal4mac]

But here is where you need to think on how the public would interpret something like that.

I totally agree. The BBC should have broadcast many hours of public debate with Rees, Kent CERN scientists, etc. Then matters of interpretation could have been fully dealt with and, hopefully, death threats avoided. But the level of public debate, at least in the UK, is severly limited. The BBC are totally failing their public service remit in not fully delving into issues like this.

One has to understand that in physics, almost everything has a non-zero probability of happening. There is a minute, but still, non-zero probability of an proton-antiproton pair appearing spontaneously out of thin air with enough energy that the LHC is producing to cause the same collision. Do we need to be worried about that?

No physicists are arguing that this is a serious threat. Some physicists are arguing that the LHC is a threat, albeit a remote one.

Ask someone off the street how likely he/she think that a broken vase, when thrown onto the ground, would reassemble itself back into the vase? That person will likely tell you that it is NOT going to happen. Yet, in physics, there is still a non-zero but miniscule phase space where such an even CAN happen. So you have a general public that has decided that such an event is impossible, and physics that says that it most likely won't happen, but still, has a non-zero probability. Do we confuse the public by telling them that it cannot happen, or do we say, it won't likely to happen, but there's still a small probability that it can? How small are we talking about? Do we then have to make comparisons with things they know like being striked by lightning?

We tell them the truth, of course!

One simply cannot spew off statements to someone without understanding the level of comprehension of the listener. You may be saying one thing, but what you said can easily be misinterpreted by the listener. That is what scientists must always guard against. If I say that the formation of a catastrophic black hole at the LHC won't occur, I am using the level of understanding of a typical person who has already accepted that the vase will NOT reassemble itself from the hundred of pieces. If one accept that as not happening, then one should also accept other events with similar or lower probability of occurring.

And then "the Dail Mail" newspaper takes an out of context quote from Rees' book saying exactly the opposite to you. So not only do they frighten the reader about black holes but they show that physicists are either disagreeing with each other on this mattere of deadly concern, or one of them is lying, or one of then is treating the public like idiots. Why not just tell then the truth in terms they can understand -- like saying the risk is the same as the same person winning the lottery x weeks in a row

 

[mal4mac]

There are very high-energetic particles out there in space, you know. Particles which have millions or billions of times more energy than what we give them in the LHC..

Yup I've taken courses in astrophysics, and so has Rees :-) My point, actually Rees', still stands.

 

[ZapperZ]

I totally agree. The BBC should have broadcast many hours of public debate with Rees, Kent CERN scientists, etc. Then matters of interpretation could have been fully dealt with and, hopefully, death threats avoided. But the level of public debate, at least in the UK, is severly limited. The BBC are totally failing their public service remit in not fully delving into issues like this.

And then "the Dail Mail" newspaper takes an out of context quote from Rees' book saying exactly the opposite to you. So not only do they frighten the reader about black holes but they show that physicists are either disagreeing with each other on this mattere of deadly concern, or one of them is lying, or one of then is treating the public like idiots. Why not just tell then the truth in terms they can understand -- like saying the risk is the same as the same person winning the lottery x weeks in a row

I'm sorry but I don't understand your point. Are you saying that Martin Rees actually argued that the LHC will create a catastrophic black hole? Seriously?

Zz.

 

[malty]

I'm sorry but I don't understand your point. Are you saying that Martin Rees actually argued that the LHC will create a catastrophic black hole? Seriously?

Zz.

Nah, because we can't deny the possibility of a catastrophic black hole happening, the Mail is arguing that we're saying it can happen!

 

[mal4mac]

You might not have been following "Islamic Science", which is sort of the muslim world's answer to creationism. They certainly think of genies - or djinn - as real.

I don't take this kind of Islamic science as being serious, and neither does anyone with a serious claim to gatekeeper status in Western science. I'm talking about the kind of science that Martin Rees [President of the RS, Newton's heir, highest post holder in UK science] holds serious.

I also don't think the world-eating black holes are "seriously suggested" either, at least not by anyone with a level of understanding sufficient to be serious. These putative objects, as has been pointed out by several people, have mutually contradictory properties. I don't see why an imaginary object with self-contradictory features is intrinsically more likely than a mythical being.

Rees and Kent suggest that the LHC poses a risk, you can find full quotes from them in this thread and others. Here's a snippet from Kent:

"... I guess a probability of 1/5000 per year probability of destroying the earth..."

If you say Rees or Kent are not knowoedgeable enough to be taken seriously then I seriously doubt your knowledge!

 

[ZapperZ]

I don't take this kind of Islamic science as being serious, and neither does anyone with a serious claim to gatekeeper status in Western science. I'm talking about the kind of science that Martin Rees [President of the RS, Newton's heir, highest post holder in UK science] holds serious.

Rees and Kent suggest that the LHC poses a risk, you can find full quotes from them in this thread and others. Here's a snippet from Kent:

"... I guess a probability of 1/5000 per year probability of destroying the earth..."

If you say Rees or Kent are not knowoedgeable enough to be taken seriously then I seriously doubt your knowledge!

Really? If he holds it that "serious", how come he has been a championed of the LHC? And he still is!

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/09/08/hadroncollider108.xml

Does that sound like someone who is concerned seriously about the LHC creating catastrophc events? He is even championing the proposed ILC and has several times criticized the STCS for dropping funding of the ILC. This is not the behavior of someone who thinks such an experiment has any possibility of such disaster!

Zz.

 

[malawi_glenn]

Why are people afraid of LHC but not cosmic radiation, which hits Earth million of million of times each second with higher energy that will be avaiable at LHC?

People who are afraid of LHC and knows about cosmic radiation are ignorant fools, according to me.

 

[mal4mac]

I'm sorry but I don't understand your point. Are you saying that Martin Rees actually argued that the LHC will create a catastrophic black hole? Seriously?

Zz.

He suggested, quoting Sheldon Glashow, that stranglets might destroy the Earth:

https://www.amazon.com/gp/product/0465068634/?tag=pfamazon01-20

(p123-126)

One chance in 50 million of killing 6 billion. Is that acceptable? That's about the same order as winning the UK lottery. People are prepared to chance the lottery, so why do they chance the LHC?

 

[ZapperZ]

He suggested, quoting Sheldon Glashow, that stranglets might destroy the Earth:

https://www.amazon.com/gp/product/0465068634/?tag=pfamazon01-20

(p123-126)

One chance in 50 million of killing 6 billion. Is that acceptable? That's about the same order as winning the UK lottery. People are prepared to chance the lottery, so why do they chance the LHC?

Why don't you ask him and see if he shares your opinion of his opinion of the LHC. The article I cited came directly from him. I don't see him mentioning even ONCE any risk associated with the LHC, and as far as I've read from a number of his articles, he has no such issues.

And unless he has published clearly how he came up with such odds, there is no way to know how and what kind of assumptions he made to arrive at such numbers. Yet, this is taken as if it is a divine prophecy, while other more detailed studies are ignored. What gives? There's no rational way to argue or discuss something like this when this is the basis of what you accept as valid.

Zz.

 

[malawi_glenn]

He suggested, quoting Sheldon Glashow, that stranglets might destroy the Earth:

https://www.amazon.com/gp/product/0465068634/?tag=pfamazon01-20

(p123-126)

One chance in 50 million of killing 6 billion. Is that acceptable? That's about the same order as winning the UK lottery. People are prepared to chance the lottery, so why do they chance the LHC?

Cosmic rays again, reach higher flux and energies than LHC.
Sir Rees' book is a popular science book, made for "scaring" people, just as horror books etc.

 

[George Jones]

If you say Rees or Kent are not knowoedgeable enough to be taken seriously then I seriously doubt your knowledge!

Rees states his take on this circus in the Telegraph article,

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/09/05/scilhc105.xml,

Rees stated "My book has been misquoted in one or two places. I would refer you to the up-to-date safety study."

Rees refers to this study

http://arxiv.org/abs/0806.3414.

 

[mal4mac]

Why are people afraid of LHC but not cosmic radiation, which hits Earth million of million of times each second with higher energy that will be avaiable at LHC?

Because, as Rees argues, the LHC is unique. Whatever cosmic radiation does, the conditions are not exactly the same as in the LHC. Are you calling Rees (President of the Royal Society) an ignorant fool?

https://www.amazon.com/gp/product/0465068634/?tag=pfamazon01-20

 

[mal4mac]

Cosmic rays again, reach higher flux and energies than LHC.
Sir Rees' book is a popular science book, made for "scaring" people, just as horror books etc.

Would you like to repeat that statement under your real name & affiliation and send it to Rees, care of the royal society?

 

[malawi_glenn]

Because, as Rees argues, the LHC is unique. Whatever cosmic radiation does, the conditions are not exactly the same as in the LHC. Are you calling Rees (President of the Royal Society) an ignorant fool?

https://www.amazon.com/gp/product/0465068634/?tag=pfamazon01-20

See George Jones post above.

Can you please state the conditions you are referring to?

 

[cristo]

Cosmic rays again, reach higher flux and energies than LHC.
Sir Rees' book is a popular science book, made for "scaring" people, just as horror books etc.

Actually, it's Lord Rees, now!

 

[malawi_glenn]

Would you like to repeat that statement under your real name & affiliation and send it to Rees, care of the royal society?

Sure, if you read GJ post ;)

 

[malawi_glenn]

Actually, it's Lord Rees, now!

Ah! Iam so sorry :-(

Lord Rees it is ;-)

 

[mal4mac]

Rees stated "My book has been misquoted in one or two places. I would refer you to the up-to-date safety study."

Notice he doesn't deny what he said in his book or say that he holds 100% with what is said in the safety report. This is a subtle diversionary tactic from an adept politican, just what you might expect from the President of the Royal Society. I've been trawling the net and listening to most of the Big Bang gumpf on radio 4 and this is the ony squeak I've heard from Rees. My guess is that he holds with what he said in his book but doesn't want the Telegraph to quote that 1 in 50 million chance! Could cause a hell of a row...

 

[malawi_glenn]

Notice he doesn't deny what he said in his book or say that he holds 100% with what is said in the safety report. This is a subtle diversionary tactic from an adept politican, just what you might expect from the President of the Royal Society. I've been trawling the net and listening to most of the Big Bang gumpf on radio 4 and this is the ony squeak I've heard from Rees. My guess is that he holds with what he said in his book but doesn't want the Telegraph to quote that 1 in 50 million chance! Could cause a hell of a row...

So where are the conditions that makes LHC more dangeours than cosmic rays? I'm waiting

The thing that matters is CM-energy.

"If some microscopic black
holes were produced by the LHC, they would also have been produced by
cosmic rays and have stopped in the Earth or some other astronomical body,
and the stability of these astronomical bodies means that they cannot be
dangerous."

From "Review of the Safety of LHC Collisions"

 

[ZapperZ]

Notice he doesn't deny what he said in his book or say that he holds 100% with what is said in the safety report. This is a subtle diversionary tactic from an adept politican, just what you might expect from the President of the Royal Society. I've been trawling the net and listening to most of the Big Bang gumpf on radio 4 and this is the ony squeak I've heard from Rees. My guess is that he holds with what he said in his book but doesn't want the Telegraph to quote that 1 in 50 million chance! Could cause a hell of a row...

But now you are doing nothing but picking and choosing what you wish to read from him. It doesn't matter that in practically ALL of his writings, he has absolutely no qualm about the LHC. This is highly consistent with what I know of him and his position on the LHC. Yet, you nitpicked one small aspect of something that he wrote, and use that as the basis of your interpretation of what HE thinks, while ignoring a consistent pattern of his opinion about this.

I think it is you who needs to identify yourself to Rees and ask him if what you think he is implying is accurate. The rest of us have read enough from Rees to know better.

Zz.

 

[tiny-tim]

Do any of you happen to know whether there's a nonzero (or greater than let's say one in a million) chance of accidental universe creation at LHC, as is sort of suggested here: http://www.newscientist.com/channel/fundamentals/mg19125591.500-create-your-own-universe.html ? If there is, then does nature do it also? It wouldn't affect us if it happened but it still seems ethically dubious.

Hi Ontoplankton!

As you say, it wouldn't affect us if it happened.

And it's not creating life …

so what is the ethical problem?

(the relevant part is:)

It's one thing to create a universe, but quite another to know where to keep it. After all, an eternally inflating universe might be expected to take up quite a bit of space - the cupboard under the stairs simply won't do.
Actually this wouldn't be a problem, Sakai says. For a start, the process warps space-time enormously, so that it is no longer the Euclidean space we are familiar with. This highly distorted space doesn't have the same geometry as normal space, so it's not as if the universe would blow up and engulf us.
Also, the baby universe has its own space-time and, as this inflates, the pressure from the true vacuum outside its walls continues to constrain it. As these forces compete, the growing baby universe is forced to bubble out from our space-time until its only connection to us is through a narrow space-time tunnel called a wormhole (see Graphic).
“Sitting inside the monopole, you would see space expanding in every direction”
In the end, space-time becomes so distorted that even this umbilical cord is severed. The baby universe's space-time is left entirely divorced from our own. If you were sitting inside the monopole, you would see space expanding, rushing out in every direction - just as it did after the big bang in our universe. The view from our universe, outside the monopole looking in, would be rather less spectacular.
“Once disconnected, the baby universe will be locked inside a microscopic black hole”
Sakai's calculations show that, once disconnected, the baby universe will be locked inside a microscopic black hole which will not appear to grow in size. This mini black hole will emit Hawking radiation and quickly evaporate from our universe. It will continue to grow its own space-time, but will leave behind little trace of its presence in our universe. "We would make this tiny little thing and before we know it, it has flown away - escaped from our grasp," Linde laments.

 

[chinatruth]

Why are people afraid of LHC but not cosmic radiation, which hits Earth million of million of times each second with higher energy that will be avaiable at LHC?

People who are afraid of LHC and knows about cosmic radiation are ignorant fools, according to me.

Maybe their understanding is: the cosmic ray hits the Earth at the speed of light, while the Earth just moves at a much lower speed.

But the rays in LHC are both at the speed of light when colliding...


Acutually, I don't know how to explain this...can anyone help?Is there any difference

 

[ZapperZ]

Maybe their understanding is: the cosmic ray hit the Earth at a speed of light, but the Earth just moves at a much lower speed.

But the rays in LHC are both at the speed of light when colliding...


Acutually, I don't know how to explain this...can anyone help?Is there any difference

Do you know what "center of mass energy" means?

Zz.

 

[malawi_glenn]

Maybe their understanding is: the cosmic ray hit the Earth at a speed of light, but the Earth just moves at a much lower speed.

But the rays in LHC are both at the speed of light when colliding...


Acutually, I don't know how to explain this...can anyone help?Is there any difference

That is not relevant, what is relevant is CM-Energy. Velocites are relative, c.f Special Relativity ala Einstein. There is always a frame which the Earth and the cosmic ray is going with same speed with respect to each other and physics is same in all frames...

 

[chinatruth]

Do you know what "center of mass energy" means?

Zz.

In a particle collision, the energy that can go into making new particles. For a collider experiment where two beams of equal energy collide head-on, this is simply the sum of the energy of the two beams. In fixed target experiments, in which a beam of particles strikes a stationary target, the center-of-mass energy is significantly less than the sum of the energies of the two colliding particles.

According to this, the energy can rise up to 14Tev in LHC, still significantly less than the energy released by the cosmic rays hitting the earth..



Am I right?

 

[malawi_glenn]

Yes, and in Earth frame, the cosmic rays and Earth is acting like a fixed targed experiment in space :-) But due to the very high (order 10000GeV) of the cosmic ray energy in Earth frame, the CM-energy is much much larger than at LHC. And this cosmic ray experiment have been going on for million of million of years. So there is noting unique in LHC, at LHC we do this in a controlled way an within a limt position in space so we can surrond the interaction point with detectors and see what happens.

 

[PompeyBloke]

Hi you lot. I am new to all this and was just wondering what happens to the new partices that are created in collisions?

 

[chinatruth]

Hi you lot. I am new to all this and was just wondering what happens to the new partices that are created in collisions?

just read through this thread and it will really help, I am also new here just for a few days.(but still older than you :!))

 

[humanino]

In a particle collision, the energy that can go into making new particles. For a collider experiment where two beams of equal energy collide head-on, this is simply the sum of the energy of the two beams. In fixed target experiments, in which a beam of particles strikes a stationary target, the center-of-mass energy is significantly less than the sum of the energies of the two colliding particles.

According to this, the energy can rise up to 14Tev in LHC, still significantly less than the energy released by the cosmic rays hitting the earth..



Am I right?

Do you really think we are that stupid ?

http://www.daviddarling.info/encyclopedia/C/center-of-mass_energy.html

 

[grahamolga]

LHC question

I'm just writing as I have a query about the LHC. As I have been thinking about this, which is weird for me (I train people in management and customer service etc) no science back ground. I would love to hear your thoughts. So here goes...

If the streams are being smashed into each other could this then create a universe? I ask this as I'm thinking the collisions the cern guys are doing under controlled conditions to look for new particles etc must already happen out there in space or here on earth/both...but are the speeds important ? Do individual natural collisions happen at lower speeds an therefore not set off a "birth"

If the particles (sorry can't remember the name) are not seen on this experiment. Do we need to go bigger/faster? Will it prove/show anything we don't already know or understand. I can't wait to find out what happens! :-) One of my colleagues said to me today what a waste ...just like space it only gave us Teflon. my immediate response was actually Velcro as well. ha haaa I must look up all the medical stuff and other thousands of things that have been of benefit to us!

Look forward to reading your thoughts.

Take care
Graham

 

[chinatruth]

Do you really think we are that stupid ?

http://www.daviddarling.info/encyclopedia/C/center-of-mass_energy.html

i didnot mean that... actually I am an amateur in physics...